How To Determine Soil Health
' '''Soil is a vital component to urban agricultural success. Here, how to determine soil health is explained. '''Soil Basics' Soil is a lot more than just dirt. Essentially, soil is a mixture of mineral (sand, silt, and clay) and organic (stuff that is, or at one time was, living) materials affected by climate and organisms over time, which provide a foundation for plants to grow in.Soil health: soil management. (2014). Penn State College of Agricultural Sciences. Retrieved from http://extension.psu.edu/agronomy-guide/cm/sec1/sec11b Soil in an urban environment is typically heavily modified through non-native soil additions, construction, and compression.United States Environmental Protection Agency. (2011). Evaluation of urban soils: suitability for green infrastructure or urban agriculture. Retrieved March 1, 2014, from http://water.epa.gov/infrastructure/greeninfrastructure/upload/Evaluation-of-Urban-Soils.pdf Studies have found that many urban soils are compressed, have low organic content, as well as contain harmful pollutants.United States Environmental Protection Agency. (2011). n.p. This means – in terms of health – that soil in a city can be very different from soil in the countryside or on a farm. Moreover, much like a meal depends on the quality of its ingredients, so too, a plant depends on the quality of its soil. Healthy soil works for growing crops and plants by allowing the inward movement and storage of water, keeping and cycling nutrients, keeping out weeds and pests, pulling out harmful chemicals, and producing bigger, healthier food.Abawi, G.S., Gugino, B.K, Idowu, O.J., Moebius-Clune, B.N., Schindelbeck, R.R., Thies, J.E., … Woulfe, D.W. (2009). Cornell soil health assessment training manual (2nd ed.). ''Retrieved from http://soilhealth.cals.cornell.edu/extension/manual/manual.pdf Therefore, the question becomes: How can you determine a soil's health? '''Quick Ways to Determine Soil Health' There is no foolproof way to determine the health of a soil just by looking at it. However, there are certain visual indicators that may help determine the state of a soil, and while they are not absolute, they are useful first steps. Testing the surface tension and hardness with a pencil or similar instrument will give some indicator as to the soil's compaction; indeed, if the tool sinks in easily, the soil is less compacted and will allow the plant roots to spread more easily and water to move more efficiently.Abawi, et al. (2009). n.p. However, this is only one indicator, as the composition and texture of the soil are also important to consider. A useful tool for discovering the soil's stability is to put some soil into a sieve (much like a wire window screen) and move it up and down in a water bath. If the soil flows through the sieve, the stability is low. Conversely, the more soil that stays in the sieve, the higher the soil stability, which will allow greater water infiltration and air movement for plants to grow.Soil health: soil management. (2014). n.p. Another great indicator of soil health is evidence of roots. In order to examine them, dig up one cubic foot of soil, preferably while the soil is moist.Ibid. The more roots and root residue (they will look like thick hairs), the healthier the soil. Darker soil under the surface is also an indicator of fertility.Abawi, et al. (2009). n.p. Additionally, using the hole you dug, you can test how well water moves through the soil. Fill the hole with roughly 3 inches of water, and if it drains in less than 20 minutes, the soil is probably well-suited for most crops.United States Environmental Protection Agency. (2011). n.p. Finding Out More Before considering any growing activity on an urban plot, you should learn about that land's history. Areas that have been used for commercial or industrial purposes – known as “brownfield” sites – can contain dangerous chemicals and pollutants, such as lead, cadmium, arsenic, and zinc.United States Environmental Protection Agency. (2011). Reusing potentially contaminated landscapes: growing gardens in urban soils. Retrieved March 3, 2014, from http://www.cluin.org/download/misc/urban_gardening_fact_sheet.pdf When concentrated in the soil, these toxins can be hazardous to the health of the crops, as well as gardeners.Ibid. Even some residential soils may not be as healthy as possible, and the fix may be as simple as adding a proper fertilizer. To find out for sure, it may be helpful to have the soil tested by a laboratory. Most state universities and many state environmental agencies can provide soil testing kits with instructions for proper sample collection. Institutions such as the University of Minnesota, North Dakota State University, Iowa State University, and the University of Wisconsin-Madison are all great places to start. For a small fee, they will test the soil and provide a detailed summary of its health, such as pH and nutrient levels.Abawi, et al. (2009). n.p. The organization can help you decode the results, which will help you plan both short-term and long-term solutions for improving your soil. ----